cDNA clones coding for the epidermal growth factor receptor were isolated from a cDNA library prepared from A431 cells, a human epidermoid carcinoma. The total sequence of one of these clones which codes for the midportion of the EGF receptor has been determined. Using this clone, it has been shown that the EGF receptor is 30-fold amplified in A431 cells and also amplified in other squamous cell carcinomas. The promoter region of the EGF receptor has been identified and its DNA sequence determined.